Means for closing an open telegraph-circuit at a distant key.



. o. B. JBWBLL. l MEANS FOB CLOSING AN OPEN TELEGRAPH G IBGUIT AT A DISTANT KEY.

APPLICATION FILED 15.3.14. 1908 908,888, Patented Ja.11.5, 1909.

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t) l' 'Y c. B. JEWELL. y MEANS EOE CLOSING AN OPEN TELEGEAPH CIRCUIT AT 'A DISTANT KEY.

APILICATION FILEDl IAB.. 14. 1903.

908,868. Patented Jan. 5, 1909.

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UNITED sTATEs PATENT oEErcE.

CARL BENNETT JEWELL, OF LA JUNTA, COLORADO.

MEANS FOB CLOSING AN OPEN TELEGBAPH-CIRCUIT AT A DISTAN T KEY.

Bpecication of Letters Patent.

Patented Jan. 5, 1909.

To all 'whom 'it may concern:

Be it known that I, CARL BENNETT JEW- ELL, a citizen of the'United States, and a resident of La Junta, in the county of Otero and State of Colorado, have made certain new and useful lm rovements in Means for Closing an Open elegra h-Circuit at a Distant Key, of which the fol owing is a specification.

The obj ect of my invention is to avoid the loss of time and extra labor that is required to run down opens on a simplex telegraph circuit, 99 7g of which are caused by the careless manner in which the operator regards his key, resulting in the inadvertent leaving of the same open and the temporary disabling of the line. On long circuits where there are 30 or 40 offices there is always considerable time lost in running down these openstime lost not only on the open wire but on the Wire used for the testi urpose. My invention is designed to avoIil/lt is so that the circuit can be closed immediately after the wire opens. Under the present system, if the wire opens it will take the wire chief anywhere from 15 minutes to one hour to run the trouble down and get the key closed, the wire in the meantime being out of commission.

The advantages of my invention will be es ecially appreciated by train despatchers w o by the nature of things are badly handicapped if they lose their wire for any length of time. They can with my invention close the circuit at their own free will without having to notify the wire chief, or wait for a certain time to elapse so that any clock arrangement will have time to do its work. The important value of my invention is to correct the difficulty prom tly as the clock works or the wire chief may e just a minute too late. On branch lines where there is only one wire it will be a trouble saver.

The main feature of my invention consists in the provision at a terminal office of an extra switch andcircuit, and an extra battery of such higher voltage than the ordinary working batteries that when the battery of higher voltage is switched on to the line wire, it will force its current through the resistance around any o en key and, by working the relay of that lkey, apprise the forgetful operator at that station that he has left his key open and thus Yinstruct him to close it.

In the drawing-Figure 1 is a diagrammatic view of a simplex telegraph line with.

my invention applied to the same, the line bei closed through closed keys. Fig. 2 is a s' ar -view with the key K2 at a middle station open and the line thereb7 rendered inoperative, and Figj?, is a simi a ing the middle key K2 open but with the line closed and operative through the agency of my invention.

In all three ures of the drawing the three stations A, ,0, are similarly equipped and with the terminal batteries marked 25 V constitute an ordinary simplex telegraph, in which `a resistance at each station, marked 3700 ohms, is bridged around the key and which resistance, when the key is open, ordinarily affords a sufficient check to the flow of the current to permit the release ofthe armature of the relay of that station, My invent-ion rovides the additional battery of highvo ta e shown in the right of each gure and mar ed 150 V and a switch S by means of which either the small battery, 25 V or the lar e battery 150 V ma be thrown on to the ine. y

eferrin now to Fig. 1, this view shows the norma condition of a sim lex circuit when all the keys are closed an the circuit is closed. The length of the line shown is 30 miles. Station A and C are the battery ends of the line.

750 ohms vThe switch S is turned to the extreme left in this view which uts 25 volts to the line whlch is met by 25 volts from the other terminus, makino' a total of 50 volts, each cell having an` internal resistance of 2 ohms the total internal resistance 100 Total -v- 1,300

50 volts X 1090i@ 18W 13)35g0(38imi1-amperes r view show- According to Ohms law we have milamperes which is suflicient to work the relays satisfactorily. closed as shown in this view the current 5 will seek the shortest route to the ground, which is through the key and not through the 3,700 ohms in the resistance coil that bridges the key.

Referring now to Fig. 2, this view shows the key K2 at station B open or in the act of making a space.

750 ohms 450 100 Total-- 5,000 The battery voltage in this instance is t-he same as in Fig. l, i. e., fifty volts.

1o M) volts X 1W@ MM50 ohms According to Ohms law we have 10 milam eres which will not work lthe relay.

`ig. 1 explains .that when the key is closed there is a current of 38112- mil-amperes to the line and Fig. 2 explains that when vthe key is open there is but l0 mil-amperes to the line; hence by simply lopening and closing the `key we change the current in :10 mil-amperes.

the line from `38%- mils when closed, to-

10 mils when open. When the key is open :the resistance coil is thrown in the circuit but when the key is closed again the yresistance coil is out out by reason of a shorter route. When therefore any key at A, B, C, is open the line is inoperative.

Referring now to Fig. 3, this view shows the key K2 open but the line closed for operative use through the agency o'fmy invention'. All that has .been necessary to obtain this result was for the wire chief or chief deof switch S from the extreme left to .the eX- treme right, 1l. e. from a to c. In so doing he has added 125 cells more or `150 cells in all and the ytotal voltage now is 175 volts as follows- 15o vat o 25 v at A 175 volts.

When the keys are allv spatcher to change the position of the lever` Each cell having an internal resistance of 2 65 ohms, the total internal resistance 350 ohms Line 750 Relay 450 Resistance co1`l 3700 70 Total 5250 im vous 1009);@

bti() ohms 3)10g(33m11amperes. 75

' According to Ohms law we have 33% milamperes which will work the relays of kthe circuit satisfactorily .until the operator can be told to close his key. The wire can now be worked and the relay at the station where the open occurs is still in an operative circuit andthe operator can be called up and told to close his key at the first opportunity, at which time the lever of switch S can be moved back to its normal position at the left.

I claiml. The combination with a telegraphic. circuit having at its `stations relays and keys and resistances bridged across the keys, a source of electro-motive force adjusted in relation to the resistances and relays to release the relay armature when the key is open, by virtue of the resistance; of a separate circuit at the end of the line, a source of electromotive force arranged Within the same larger than the normal working electro-motive force and adjusted in relation to the resistances and relays to operate any relay through the resistance of that station when the key of lthat station is open.

2. The combination witha telegraphic circuit having at its stations relays and keys and resistances bridged across the keys, a source of electro-motive force adjusted in relation to the resistances and relays to release the relay armature when the key is open, by virtue of the resistance; of a separate circuit at the end of the line, a source of electromotive force arranged within the same larger than the normal working electro-.motive force and adjusted in relation to the resistances and relays to operate any relay through the resistance of that station when the key of that station is open, .and means for throwing the excessive electro-motive force on the line.

3. The combination with a telegraphic circuit having at its stations relays and keys and resistances bridged across the keys, a source of electro-motive forceadjusted in relation to the resistances and relays to release the relay armature when the key'is open, by virtue of the resistance; of a separate circuit 125 at 'the end Vof the line, a source of electro- `motive forcearranged withinthe same larger y vthan the normal working electro-motive force and adjusted in relation to the resistances batteries at the end; of a second circuit conand relays to operate any relay through the tainin a battery of larger voltage than the resistance of that station When the key of norml Working battery, said battery of that station is open, and a switch for throW- larger Voltage being adjusted to operate the 5 ing either the normal Working electro-motive relay of an key through its resistance when 15 force on to the line or the excessive electrothe key is eft o en.

motive force on to the line as desired. CAR BENNETT J EWELL.

4. The combination with a simplex tele- Witnesses: gra h embodying keys, relays, resistanoes E. JQGILMAN,

10 bri ged across the keys, and normal Working C. L. SEELEY. 

